Improving hydrophilicity, mechanical properties and biocompatibility of poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate] through blending with poly[(R)-3-hydroxybutyrate]-alt-poly(ethylene oxide).

Natural source poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate] (PHBV) with a low hydroxyvalerate (HV) content ( approximately 8wt.%) was modified by blending it with poly[(R)-3-hydroxybutyrate]-alt-poly(ethylene oxide) (HE) alternating block copolymer. We hypothesized that the adjoining PHB segments could improve the miscibility of the poly(ethylene oxide) segments of HE with the PHBV matrix and therefore improve the physical properties of the PHBV/HE blends. A differential scanning calorimetry study revealed the improved miscibility of PEO segments of HE characterized by the interference of the crystallization of PHBV. The decrease in water contact angle and the increase in equilibrium water uptake of the PHBV/HE blends indicated that both the surface and bulk hydrophilicity of PHBV could be improved through blending HE. The mechanical properties of the hydrated PHBV/HE blends were assessed by measuring their tensile strength. In contrast to the hydrated natural source PHBV, which failed in a brittle manner, the hydrated PHBV/HE blends were ductile. Their strain at break increased with increasing HE content, reaching a maximum of 394% at an HE content of 15wt.%. The excellent integrity of the PHBV/HE blends in water is attributed to the strong affinity between the PHB segments of HE and the PHBV matrix. Platelet adhesion on the film surface of the PHBV/HE blends was investigated in vitro to evaluate their blood compatibility. The results demonstrated that the PHBV/HE blends effectively resisted the adhesion of platelets due to the anchored PEO segments from HE on the film surface.

[1]  Xian Jun Loh,et al.  New biodegradable thermogelling copolymers having very low gelation concentrations. , 2007, Biomacromolecules.

[2]  Seeram Ramakrishna,et al.  Micellization phenomena of biodegradable amphiphilic triblock copolymers consisting of poly(beta-hydroxyalkanoic acid) and poly(ethylene oxide). , 2005, Langmuir : the ACS journal of surfaces and colloids.

[3]  Jun Li,et al.  The in vitro hydrolysis of poly(ester urethane)s consisting of poly[(R)-3-hydroxybutyrate] and poly(ethylene glycol). , 2006, Biomaterials.

[4]  Jun Li,et al.  Poly(ester urethane)s consisting of poly[(R)-3-hydroxybutyrate] and poly(ethylene glycol) as candidate biomaterials: characterization and mechanical property study. , 2005, Biomacromolecules.

[5]  R. Marchessault,et al.  Bacterial polyesters: biosynthesis, biodegradable plastics and biotechnology. , 2005, Biomacromolecules.

[6]  E. Topol,et al.  Marked inflammatory sequelae to implantation of biodegradable and nonbiodegradable polymers in porcine coronary arteries. , 1996, Circulation.

[7]  D. M. Kim,et al.  Platelet adhesion onto segmented polyurethane film surfaces modified by addition and crosslinking of PEO-containing block copolymers. , 2000, Biomaterials.

[8]  P. Supaphol,et al.  Bone scaffolds from electrospun fiber mats of poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and their blend , 2007 .

[9]  D. Kumar,et al.  Chemical modification of poly(vinyl chloride) resin using poly(ethylene glycol) to improve blood compatibility. , 2005, Biomaterials.

[10]  Jun Li,et al.  Hydrolytic degradation and protein release studies of thermogelling polyurethane copolymers consisting of poly[(R)-3-hydroxybutyrate], poly(ethylene glycol), and poly(propylene glycol). , 2007, Biomaterials.

[11]  M. Mackay,et al.  Unusual mechanical performance of amphiphilic crosslinked polymer networks. , 2007, Journal of the American Chemical Society.

[12]  Kam W Leong,et al.  Dynamic and static light scattering studies on self-aggregation behavior of biodegradable amphiphilic poly(ethylene oxide)-poly[(R)-3-hydroxybutyrate]-poly(ethylene oxide) triblock copolymers in aqueous solution. , 2006, The journal of physical chemistry. B.

[13]  Guoqiang Chen,et al.  The application of polyhydroxyalkanoates as tissue engineering materials. , 2005, Biomaterials.

[14]  L. M. Chan,et al.  Synthesis, characterization, and morphology studies of biodegradable amphiphilic poly[(R)-3-hydroxybutyrate]-alt-poly(ethylene glycol) multiblock copolymers. , 2006, Biomacromolecules.

[15]  Linbo Wu,et al.  "Wet-state" mechanical properties of three-dimensional polyester porous scaffolds. , 2006, Journal of biomedical materials research. Part A.

[16]  Wantai Yang,et al.  Miscibility and crystallization behavior of biodegradable blends of two aliphatic polyesters. Poly(3-hydroxybutyrate-co-hydroxyvalerate) and poly(ε-caprolactone) , 2005 .

[17]  Jun Li,et al.  Synthesis and Characterization of New Biodegradable Amphiphilic Poly(ethylene oxide)-b-poly[(R)-3-hydroxy butyrate]-b-poly(ethylene oxide) Triblock Copolymers , 2003 .

[18]  Y. Doi,et al.  Crystalline and thermal properties of bacterial copolyesters: poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) , 1989 .

[19]  Interactions of ADP-stimulated human platelets with PEGylated polystyrene substrates prepared by surface amidation. , 2007, Colloids and surfaces. B, Biointerfaces.

[20]  M. Maitz,et al.  Current strategies towards hemocompatible coatings , 2007 .

[21]  J. M. Harris,et al.  Poly(Ethylene Glycol) Chemistry , 1992 .

[22]  M. L. Focarete,et al.  Polymer Blends of Natural Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and a Synthetic Atactic Poly(3-hydroxybutyrate). Characterization and Biodegradation Studies , 1997 .

[23]  E. Giménez,et al.  The effect of ethylene content on the interaction between ethylene-vinyl alcohol copolymers and water—II: Influence of water sorption on the mechanical properties of EVOH copolymers , 2006 .

[24]  Orawan Suwantong,et al.  Electrospun fiber mats of poly(3‐hydroxybutyrate), poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate), and their blends , 2006 .

[25]  H. Kammer,et al.  Crystallization and melting behavior of blends comprising poly(3-hydroxy butyrate-co-3-hydroxy valerate) and poly(ethylene oxide) , 2006 .

[26]  A. Mayes,et al.  Polysulfone-graft-poly(ethylene glycol) graft copolymers for surface modification of polysulfone membranes. , 2006, Biomaterials.